Box strapping machine



April 21, 1959 A. L. WINKLER ET AL 2,882,814

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BOX STRAPPING MACHINE Filed April 26, 1952 1s Sheets-Sheet 5 IN VENTORSI- e iadgzg a April 21, 1959 A. L. WINKLER ET AL 2,882,814

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BOX STRAPPING MACHINE April 21, 1959 16 Sheets-Sheet 5 Filed April 26,1952 I INVENTORSJ; I CZZz/L'n/Z. ZZ/L' jZaerZfi ZH April 1959 A. L.WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE l6 Sheets-Sheet 6 Filed April 26, 1952 Illll l l ll l |||L|||| INVENTORSI A nl 21, 1959 A. L. WINKLER ET AL 2,882,314

' BOX STRAPPING MACHINE Filed April 26, 1952 l6 Sheets-Sheet 7INVENTORS. I

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BOX STRAPPING MACHINE 16 Sheets-Sheet 11 Filed April 26, 1952 IN VENTORS 6212/07/17. ZZ/inkler; flaberifi 15%81; 5 T5872 April 21, 1959 i A.WINKLER ETAL 2,882,314

BOX STRAPPING MACHINE Filed April 26, 1952' 16 Sheets-Sheet 12 I l lINVENTORS. CZZz/L'nl ZZ/zLn/der flabert E17 827 April 21, 1959 A.WINKLER El'AL 2,8

BOX STRAPPING MACHINE Filed April 26, 1952 1s Sheets-Sheet 1s April 1959A. L. WINKLER ETAL 2,882,814

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April 1959 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE Filed April 26, 1952 16 Sheets-Sheet 15 UnitedStates Patent i 2,882,814: BOX STRAPPING. MACHINE L2 Winkle'r',ChicagmRob'ert'E. Hager, Park Forest, and Kjell A. FalcloPedersen,Cicero, 111., assignorsto AcmetSteel Companygzchicago', 111., acorporation of Illinois.

AppIicationJApriH'G, 1952, Serial No. 284,634 STClaii'ns: (6.100e-25)-This" invention relates to box: strapping machines'and its'pu'rpose isto provide animproved machine for applyiug a flexible binder, such a's'aflat metal strap, about a-boxor package, drawing the binder taut,cutting it all from the'source-of supply and then uniting itsoverlappingends. The primary object of the invention is to provide an improvedmachine in which all of the operations just mentioned," exceptfor aninitial operation of'extending the .binderpartially around the box orpackage, are performed automatically in proper sequence and timedrelation'without any attention: on the part of theoperator.

In the operation of the machine, the completion of one binding operationleaves 'a predetermined length of str'apin a positionsuch that itpartially encircles a package when the package is placed in bindingposition. After placing the package in that position the operator pullsout the free end of the strap and completes the encirclemeut of thepackage with the free end of the strap in a position to be gripped bythe mechanism, whereupon the automatic. operations are initiated and thefree end of the strap is gripped, the slack in the strap then-taken upby reversing the strap feeding means, the strap then positively-drawntaut to a predetermined degree bythe movement of a strap gripping deviceengaging the supply portion of :the strap, the supply portion then heldby a stationary gripping device, the supply portion then cutoff, a jointformed betweenthe ends of the tensioned strap, and the strap and packagethen released from the gripping mechanism.

One difliculty with the operation of prior box strapping machineshasbeen that the strap has generally been dr'awntaut about the box bypulling mechanism which depends upon the-slipping of a clutch or thelike to terminate .the: tensioning 'operation and it has been foundthat'the straptisnot'thereby drawn taut to the same degree? whenappliedzto different boxes. Itis one of the principal objects of thepresentinvention to provide improved mechanism for positively grippingthe strap and-'drawingittaut to' substantially the same degree insuccessive operations on different boxes or packages. A further objectofthe: invention is to provide improved means'whereby' any desired degreeof tension, withina wide range, may-be created with accuracy in thestrap surrounding the package. Another objectisto provide means forinsuring the operation of the strap tensioning mechanism only after theslack in the strap encircling the-package has-been. removed. Otherobjects relate to various features of-constructionand arrangement whichwill appear more fully hereinafter.

Thev nature-of the invention will be-understood from the followingspecificationtakenwith the accompanying drawings in which one-embodimentof the. invention .and' amodification of apart thereof are illustrated.In the drawings,

Figure 1 shows a perspective view of a; preferred:

embodiment ofthe invention;

'ice

which has been bound with the use of the machine illustrated in Fig. 1;

Fig. 3 shows a top plan view of the overlappingends of the strap whichextends around thebox shown in Fig. 2 with th'eseends united by means ofspot welds;

Fig. 4a is a somewhat diagrammatic view of-some of the principal partsof theboxv strapping machine; illustrated in Fig. 1, showing therelation of the binding strapto theqboxx'when thexbox'is first placedfinposition to be bound and before the strap has been caused. to encirclethebox;

Fig; 4b is a diagrammatic view-similarito thattof Fig. 4a showing thecondition after thefreeend of the strap: has been manually. moved aboutthe box by the operator and its end inserted in a guide beneath the box;

Fig. 4c is. a diagrammatic view. similar to thoseof Figs; 4a and 4billustrating the condition after the free endof the strap has .beengripped beneath the box and after the feeding mechanism has: started areverse operation for the purpose of taking up the slack in the strapwhich" encircles the box;

Fig. 4d is a view similar to that ofFig; 4c showing the condition aftertheslack in the strap has been taken up so that the strap is in closecontact with the box on three sides thereof and after the supply portionof the strap has been gripped by a movable gripping device which hasstarted its movement for'drawing the strap taut around the box;

Fig. 4e is a diagrammatic view similar to, that of Fig. 4d showing therelative arrangement: of the parts after the movable gripping device hasmoved further to draw the strap taut and after astationary grippingdevice has started its movement toward a position: wherein it grips thesupply portion of the strap;

Fig. 4, is a view similar to that of Fig. 42 showing the condition at alater stage when the movablegripping device has passed-out of engagementwith the strap, a stationary gripping dog has moved into grippingengage. ment with the supply portion of the strap, the strap has beensevered by shearing blades, and the welding device has started itsmovement toward the welding position;

Fig. 4g shows a diagrammatic view similar to that of Fig. 4 with thewelding device in the position toweld the overlapping ends of the strapwhich is then held by the two, stationary gripping devices beneath thebox;

Fig. 4h, shows a diagrammatic view similar to that of Fig. 4g,illustrating the condition after an ejecting: device has moved the boundbox out ofengagement with the gripping devices, and the gripping dogs as.well as the welding device have been retracted so that the. parts arethen in readiness for a new binding operation;

Fig. Sshows a front elevation of the machine-illus trated in Fig. 1 withthe casing removed to reveal the internal mechanism;

Fig. 6 shows an end elevation of the machine illustrated in Fig. 5,looking-toward the right as viewed in Fig. 5;

Fig. 7 shows a top plan view of the machine illustrated in Fig. 5; 1

Fig. 8 shows apartial vertical section taken on the line 8'8 of Fig. 7'showing the stationary grippingdogs, the welding device, and otherassociated parts of the apparatus;

Fig. 9 shows a sectional view taken on the line 99 of Fig. 6;

Fig. 10 shows a sectional view taken on the line 10..-10. of Fig. 5;

Fig; 11 shows a sectional view taken on the line ll ll' of-Fig. 10;

Fig. 12 is .a view similarto thatofFig. 11 showingthe relative positionsofrthe parts of the, shearingymechanism when they are in the extendedposition wherein the shear- 14-14 of Fig.5;

Fig. 15 shows a sectional view taken on the line 15-45 of Fig. 14; pFig. 16 shows a sectional viewtaken on the line 16 16 of Fig.

Fig. 17 shows a sectional view taken on the line 17 17 of Fig. 16;

Fig. 18 is a sectional view similar to that of Fig. 16 showing the straptensioning mechanism when it is in its extreme tensioning position;

Fig. 19 shows a partial sectional view taken on the line 19-19 of Fig.18; L'Fig. 20 shows a side elevation of the strap tensioning grippingdog and its associated parts at that time in the operating cycle whenthe strap tensioning mechanism is about to start its operation;

Fig. 21 is a view similar to that of Fig. 20 illustrating the relativepositions of the parts a short interval after the strap tensioningoperation has started;

Fig. 22 is a view similar to that of Fig. 21 illustrating the straptensioning parts when they are in the elevated position corresponding tothat shown in Fig. 16;

Fig. 23 shows the parts of the strap tensioning mechanism after thestrap tensioning dog has gripped the strap and has started its downwardmovement as illustrated by dotted lines;

Fig. 24 shows the strap tensioning mechanism in its lowermost positionafter the strap has been drawn taut around the box or package;

Fig. 25 shows the parts of the strap tensioning mechanism illustrated inFig. 24 after these parts have started to return to their normal upperpositions;

Fig. 26 is a view similar to that of Fig. 16 showing a modified form ofmeans for loading the strap tensioning mechanism;

Fig. 27 shows a top plan view of the modified mechanism illustrated inFig. 26; and

Fig. 28 shows a schematic diagram of the electrical system by whichvarious parts of the machine are operated and controlled.

As illustrated in the drawings, particularly in Fig. 1, the invention isembodied in a box strapping machine comprising a casing 30 which is madeup of a sheet metal shell 31 surrounding an internal frame structurewhich supports the movable parts of the mechanism. This casing 30 isopen at its top but is normally closed by a lid or cover 32 which ishinged at 33 on the casing so that it may be tilted upwardly to theposition shown by dotted lines in order to gain access to the mechanismwithin the casing. The lid or cover 32 serves as a table on which thebox strapping operations are carried on. For this purpose, the table isprovided with a recess in which are mounted a series of rollers 34extending for a considerable distance from one end of the table and,adjacent the other end, the table is recessed to accommodate a lessernumber of rollers 35. All of these rollers project slightly above thetop surface of the table and serve as conveyors over which the boxes orpackages may be conveniently moved to and from the strapping position.Between the two series of rollers, there is mounted a welding device 36which is adapted to unite the overlapping ends of a strap passed aroundthe package. The table is provided with a groove 32a adapted to receivethe strap which is passed around the package and, at the rear of thetable, there is mounted a guide 37 having a vertical groove 37a thereinwhich is adapted to receive the strap 40 when it is projected upwardlyfrom the interior of the casing as shown in Fig. 1 and to permit theforward looping of this strap about the box or package which ispositioned over the welding device 36 when the binding operation iscarried on. At the forward side of the table 32, there is provided apanel 41 on which are mounted a series of knobs 42, 43 and 44 forcontrolling the operation of various parts of the apparatus which aredesignated, respectively, by the numerals 450, 445 and 528 in Fig. 28.Beneath this panel, there are mounted switches for controlling theoperating circuit including a switch 45 by which each cycle ofoperations may be initiated. At the bottom of the-casing 31, there ismounted a foot pedal 46 adapted to be manipulated by the operator tocontrol the feeding of the strap 40 from the-interior of the casing.

The strap 40 is adapted to be drawn taut around a box or package, suchas the box 50 shown in Fig. 2, and after it has been drawn taut and itssupply portion cut off, the overlapping ends are secured together toform an interlocking joint preferably by means of spot welds as shown at51 in Figs. 2 and 3. Only one strap is shown as being applied around thebox or package but, by shifting the position of the box or package onthe table 32, any desired number of straps might be applied around asingle package.

Before proceeding with a detailed description of the structure of theapparatus, reference will be made to the diagrammatic views of Figs. 4ato 4k, inclusive, which illustrate the sequence of the variousoperations which are performed from the time that the package is placedover the welding device until it has been completely bound and removedfrom the table of the machine. In these figures, certain primary partsof the apparatus are illustrated in their operative relationship lookingtoward the left-hand end of the machine as viewed in Fig. 1. Referringto Fig. 4a, the strap 40 is drawn from a supply reel (not shown) arounda guide wheel 54 between the dogs of a movable gripping device 55 andthen around a feed wheel 56 which is power driven and with which thestrap is maintained in contact by a guide wheel 57. The feed wheel 56 isadapted to feed the strap through a guide channel 58a formed in a frontgripping dog 58 which is pivoted at 59 on the frame structure and whichis provided with a series of teeth 58b adapted to cooperate with astationary gripping plate 60 in gripping the strap after it has beenpassed around the package 50. From the passage 58a of the front grippingdog 58, the strap extends through the lower guide channel 61a of a strapguide 61 which is positioned beneath the welding device 36. The strapthen extends above a rear gripping dog 62 which is pivoted at 63 on theframe structure and which is provided with a series of teeth 62!)adapted to cooperate with a stationary gripping plate 64 located beneaththe package 50. At the proper time, the rear gripping dog 62 is adaptedto be moved upwardly to cooperate with the plate 64 in holding thesupply portion of the strap after it has been drawn taut about thepackage.

At the conclusion of a strapping operation, the parts of the machinenormally come to rest in the relative positions shown in Fig. 4a withthe free end 40a of the strap curved upwardly and extending partiallyover the box 50 positioned on the table against the guide 37. In normaloperation, a sufficient length of strap will extend upwardly over thebox to permit it to be passed around the box by the operator but, if asuflicient length of strap does not extend in this manner, the operatormay step on the foot pedal 46 and thereby actuate the feeding mechanism,including the feed wheel 56, to cause the required length of strap to beprojected upwardly over the box. Assuming that the box has been placedin proper position on the table and that a sufficient length of strap ispresent, the operator then seizes this end of the strap and extends itforwardly and downwardly around the box until it extends between theforward gripping dog 58 and the stationary gripping plate 60 and intothe upper channel 61b of'the guide member 61.

This channel is closed atits end so that when the strap has been thrustinwardly to the extent permitted by the depth of the channel 61b, thebox has been completely encircled and the parts are in readiness for thecycle of automatic operations which is initiated by closing the switch45 beneath the panel 41 at the front of the machine.

When the switch 45 is closed, the front gripping dog 58 is movedupwardly from the position shown in Fig. 4b to the position shown inFig. 4c so that the free end of the strap is then gripped and heldagainst the stationary gripping plate 60 and at the same time the reargripping dog 62 begins an upward movement from the position shown inFig. 4b to an intermediate position shown in Fig. 40. When the free endof the strap 40 has thus been gripped, the feeding mechanism is reversedso that the feed wheel 56 is then rotated in the direction shown by thearrow 65 in Fig. 40 with the result that the loop of strap extendingaround the box is contracted until all of the slack has been taken outof the strap and it lies in close contact with the box under moderatetension, as shown in Fig. 4d. At the conclusion of this slack take-upthe movable gripping device 55 is actuated and its gripping dogs seizethe strap beneath the feed wheel 56 and move downwardly to continue thepull on the strap as indicated by the arrow 66 in Fig. 4d.

In Fig. 4e the relative positions of the parts are illustrated at asomewhat later stage in the operation when the movable gripping device55 has moved downwardly to a further extent and the rear gripping dog 62has moved still further in an upward direction so that an arm 62a on thefree end of this dog extends upwardly at the side of the supply portionof the strap 40 to guide the strap and keep it in alignment with thefree end of the strap which is then held by the front gripping dog 58.At this stage, the welding head 67, which has previously occupied itslowermost position, begins an upward movement from the lower positionwhich is illustrated by dotted lines. At this stage the strap shearingblades 68 have been moved to a position where they embrace the supplyportion of the strap somewhat forwardly from the position occupied bythe welding device 36. In Fig. 4f, the operation has continued to thepoint where the strap has been drawn taut around the package with apredetermined tension in it and the rear gripping dog 62 has movedupwardly to the point where it grips the supply portion of the strapagainst the plate 64 and the shearing blades 68 have been actuated tocut off the strap, leaving two ends of the strap overlapping beneath thecontacts of the welding device 36. The welding head 67 then movesupwardly from the position shown in Fig. 4) to the position shown inFig. 4g and is actuated to weld the overlapping ends of the straptogether to form the type of joint which is illustrated in Figs. 2 and3. While this welding operation is going on, the movable gripping dogsare moved out of engagement with the supply portion of the strap beneaththe feed wheel 56 and, the box having been completely bound, an ejectingdevice 69. is then actuated to engage the strap and move it out ofengagement with the gripping plates 60 and 64 at the same time that thegripping dogs 58 and 62 are moved downwardly to the position shown inFig. 4h. At the same time, the welding head 67 is moved downwardly fromthe position shown by dotted lines in Fig. 4h to the position shown byfull lines so that the parts are then in readiness for a new bindingoperation except for the final actuation of the feed wheel 56 which thentakes place to project a length of strap through the guide channel 61aof the guide 61 and upwardly through the groove 37a of the guide 37 sothat it then will curve over the welding device 56 in readiness for anew strapping operation.

Before proceeding with a detailed description of the operating mechanismof the machine, reference will be made to the frame structure whichsupports the outer shell of the cabinet 31 shown in Fig..1,. as well asthe various parts of the operatingmechanism. .Asshdivh particularly inFigs. 5, 6 and 7, this frame structure comprises four upright framemembers 75, -76, 77 and 78 which extend vertically at the corners of,the cabinet and are provided at their lower ends with horizontallyextending flanges 79 provided with apertures 79a adapted to be engagedby studs or bolts for the purpose .of securin g thecabinet to the flooror other support. Adjacent their lower ends, the vertical frame members75 and 76 are connected by a horizontal frame member 80 of angle barform and, at the rear of the machine, the lower ends of the verticalframe members 77 and 78 are similarly connected by a horizontalframemember 81 of angle bar cross section which has its top horizontalflange in the same plane as the top flange of the frame member 80. Theseframe members 80 and 81 are connected by two angle bars 82 (see Fig. 5)on which there is mounted a plate 83 arranged to serve as a support foran electric motor 85 by which most of the movable parts of the machineare actuated.

Some distance above the horizontal frame members 80 and 81 the verticalframe members 75 and 76 are connected by a horizontal channel-shapedframe member 86 which has its flange directed outwardly and which isarranged in the same horizontal plane as the correspondingchannel-shaped frame member 87 which extends between the upright framemembers 77 and 78 at the rear of the machine. The top end of the framemember 75 is connected to the top end of the frame member 77 by a bar 88and the top end of the upright frame member 76 is similarly connected tothe top end of the frame mem: ber 78 by an angle bar 89. r Adjacent theleft-hand end of the machine, as viewed in Fig. 5, the front horizontalframe member 86 is con nected to the rear horizontal frame member 87 bytwo parallel channel-shaped members 90 which have their ends welded tothe inner vertical facesfofthe members 86 and 87. The upper horizontalflanges ofthese frame members 90 have welded thereto four blocks 91 towhich are secured by bolts 92 the base flanges of a metal cast-. ing 93which serves as a supporting frame for most of the movable parts of themechanism. Toward the righthand end of the machine a pair of angle bars94 are welded at their rear ends to the horizontal frame member 87 andthese angle bars are supported toward their forward ends by uprightframe members 95 which are welded thereto at their upper ends and whichare welded at their lower ends of the plate 83 by which the motor 85 issupported. The bars 94 serve as supports for an electric transformerwhich is supported above the bars 94 by four bolts 101 which arethreaded at both endsfor engagement with apertures in the frame of thetrans: former and in the bars 94 and which are engaged bya series ofnuts 102.

Somewhat to the right of its middle point, the front horizontal framemember86 has welded thereto an upright frame member 103 which is weldedat its upper end to a horizontal frame member 104 secured at itsright-hand end to the upright frame member 76. A plate 105 is Welded tothe frame member 104 to extend downwardly therefrom and this plateserves as a support for a rotary switch 106 which is connected in theelectric op: erating circuit as hereinafter described. At the rearof themachine, the horizontal frame member 87 has secured thereto anupstanding frame member 107 which is similar to the frame member 103 andwhich is secured at its upper end to a horizontal frame member 108 cxtending to the right-hand end of the machine whereit is welded to theupright frame member 78.

At the lower left-hand end of the frame structure, the frame member 75is connected to the upright frame 'mem ber 77 by means of a horizontalframe member 109 which has bolted to the forward end thereof-a horizontal plate 110 arranged to serve as .a-support foraxhys 1 d au i pu p1.1.1 which s r an d to circulate un e p es ure the hydraulic fluidwhich is employed in the operatiouof .the machine. On the other side ofthe frame member 109, there is mounted a hydraulic cylinder 112 whichserves in conjunction with the pump 111 to regulate the tension set upin the strap 40 by the tensioning mechanism 55, as more fully describedhereinafter. At the left-hand rear corner of the cabinet, adjacent theupright frame member 77, there is mounted a hydraulic accumulator*114which is held in place by an encircling strap 11441 which isattached at one end to the frame member '77 by a stud 116 and secured atthe other end to a bracket 117 which is welded to the horizontal framemember 87. The lower end of the accumulator 114 communicates with aT-connection 115 from which one conduit 118 extends to a port at theupper end of the pump 3111 while another conduit 119 extends to the endof the cylinder 112 which is adjacent the forward side of the machine.

A cam shaft 120, extending longitudinally of the machine, is journaledin bearings mounted in the cast metal frame '93 and this cam shaft hasfixed thereon a series of cams 121, 122, 123 and 124, shown particularlyin Fig. 9, which serve to control various parts of the operatingmechanism as the cam shaft is rotated. The cam 121 operates inconjunction with the control of the tension mechanism 55, the cam 122serves to move the welding head 67 to and from its operating positionand also to actuate the forward gripping dog 58, the cam 123 operates toactuate the strap ejector 69 and the rear gripping dog 62 as well as thestrap end guide 61, and the cam 124 controls the actuation of theshearing mechanism 68.

The cam shaft 120 is driven by a belt 125 extending around a pulley 126on the shaft 127 of the motor 85 and also around a pulley 128 which isrotatably mounted on the cam shaft as shown in Figs. 6 and 9. Thepulleys 126 and 128 are provided with a pair of V-shaped grooves whichare engaged by the corresponding projections of 'V-shaped cross sectionwhich are formed on the inner side of the belt 125. At the left-hand endof the cam shaft, as viewed in Figs. 7 and 9, the shaft has fixedthereon a Sprocket gear 129 which meshes with a chain 130 having adriving engagement with a sprocket pinion 131 fixed on a feed shaft 135which is journaled at one end in a ball bearing unit 136 mounted in abearing member 137 attached to the frame 93, and at its other end in anover-running clutch 138 mounted in a bracket 139 of L-shaped form whichis secured to the frame 93 as shown particularly in Fig. "7. Theoverrunning clutch 138 permits rotation of the shaft 135 in onedirection but prevents rotation in the opposite direction. At anintermediate point the feed shaft 135 has mounted thereon the feed wheel56 bywhich the strap 40 is fed from the source of supply, this mountingbeing effected by an elongated hub portion 56a, shown in Fig. 9, whichis journaled in ball bearing units 140 and 141 mounted in the frame 93.The feed wheel 56 has a gear143 mounted on its hub and secured to theside thereof, as shown in Fig. 9, and this gear meshes with a pinion 144secured upon a countersliaft 145 which is journaled in ball bearingunits 146 and 147 mounted in the frame 93 and in the bracket 139,respectively. Thus, when the shaft 145 is actuated the pinion 144 drivesthe gear 143 and thereby actuates the strap feed wheel 56.

The cam shaft 120 also has rotatably mounted thereon a sprocket wheel148 which rotates with the pulley 128 and meshes with sprocket belt 149extending around a sprocket wheel 150 mounted to revolve about the feedshaft 135 and also about a sprocket pulley 151 which is rotatablymounted upon the countershaft 145. When the motor 85 is operated todrive the pulley 128, the connected sprocket pulley 148 issimultaneously rotated to drive the belt 149 so that both of thesprocket pulleys 148 and 151 are thereby actuated. Means are providedfor Connecting these sprocket pulleys to the shafts 135 and 145,respectively, in order to control the operation of the feed wheel 56 andthe actuation of the cam shaft on which the cams 121, 122, 123 and 124are mounted.

The sprocket pulley 151 has a long hub 151a which is mounted to revolveabout the shaft on ball hearing units 152 and 153 which are positionedagainst shoulders on an intermediate part of the shaft as shown in Fig.9. One end of the hub 151a has secured thereon a ring 155 which issecured by studs 156, metal ring 157, and pins 158 to the casing of aring-shaped electromagnet 160 which revolves with the sprocket gear 151about the shaft. Adjacent to the magnet 160 which forms a part of anelectromagnet clutch, there is mounted a complementary ring 161 which issecured upon the countershaft 145 by means of a key 162. This ring 161is provided with an annular series of apertures 161a in which there areslidably mounted plungers 163 having enlarged heads which are fastenedto an annular metallic ring made up of a member 165a of channel form anda connected flat disk 16512 which is adapted to coact with the radialface of the clutch magnet 160. Each of the plungers 163 is provided witha spring 164 which reacts between the ring 161 and the annular metallicring 165 to urge it against the clutch magnet 160. Electric current issupplied to the clutch magnet 160 by means of slip rings 166 and wires158 which are mounted upon the ring 155 and separated from each other byan anniilar insulating member 167. Brushes engaging these slip rings areconnected in the electric circuit hereinafter described and when theclutch magnet 160 is energized, the magnetizable ring 165 is attractedand held by the magnet so that the magnet and the sprocket gear 151 thenrotate the clutch member 161 with the result that the countershaft 145is thereby actuated to operate the pinion 144 and thereby drive the feedwheel 56 through the gear 143 so that the metal strap 40 is thereby fedthrough the guide member 37 to the strapping position above the table 32as heretofore described.

There is also mounted around the ,countershaft 145 an annularelectromagnet 170 which is secured by a metal ring 171 and studs 172 tothe bracket 139 carried by the frame 93. Since the magnet 170 isstationary, connec' tions to its electric winding may be made throughstationary terminal posts in the usual manner. The elec tromagnet 174),when enerziged, attracts a metallic ring 173 made up of a flat ring 173aadapted to contact with the end face of the casing of the magnet 170 andanother member 173b of channel-shaped cross section to which there issecured the enlarged ends of another series of plungers 174 which areslidably mounted in certain of the apertures 161a formed in the disk161. The plungers 174 are arranged alternately with the plungers 163around the outer portion of the disk 161 and coil springs 175 normallypress the ring 173 into engagement with the end face of the clutchmagnet 170 which serves as a brake to arrest the rotation of the shaft145 when it is energized. When the shaft 145 is rotating, the plate 173ais pressed against the end face of the magnet by the springs 175 but,upon deenergization of the clutch magnet 160, the brake magnet 170 isenergized by the operation of the electric circuit hereinafter describedso that the brake ring 173 is thereby attracted and the shaft 145 isbrought to rest. The connections of the electric circuit are such thatthe two magnets 160 and 170 cannot be energized at the same time. At theright-hand end of the shaft 145, as viewed in Fig. 9, a gear 176 isfixed to rotate with the shaft and this gear meshes with another gear177 mounted upon the shaft of the rotary switch 106, as shown in Fig. 5,so that this switch is operated to control certain parts of the electriccontrol circuit each time that the countershaft 145 is rotated.

The pulley 128 and the sprocket pulley 148, which are rotatedcontinuously when the motor 85 is in operation, operate through the belt149 to effect a simultaneous rotation of the gear 150 which has a longhub 150a

